code: def test_read_dwis():
      data, aff, bs, gs = didr.read_mosaic_dwi_dir(
          IO_DATA_PATH, "siemens_dwi_*.dcm.gz"
      )
      assert data.ndim == 4
      assert_array_almost_equal(aff, EXPECTED_AFFINE)
      assert_array_almost_equal(bs, (0, EXPECTED_PARAMS[0]))
      assert_array_almost_equal(
          gs, (np.zeros((3,)), EXPECTED_PARAMS[1])
      )
      with pytest.raises(OSError):
          didr.read_mosaic_dwi_dir("improbable")
  
file_path: nibabel/nibabel/nicom/tests/test_dicomreaders.py
imports: from os.path import join
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from nibabel.optpkg import optional_package
  from ..None import dicomreaders
  from .test_dicomwrappers import DATA, EXPECTED_AFFINE, EXPECTED_PARAMS, IO_DATA_PATH
label_desc: Use image node_id 2 for calling a global function with example usage: test_read_dwis() without return types